A compound acoustic wave filter device comprises a support substrate having an including two or more circuit connection pads. An acoustic wave filter includes a piezoelectric filter element and two or more electrodes. The acoustic wave filter is micro-transfer printed onto the support substrate. An electrical conductor electrically connects one or more of the circuit connection pads to one or more of the electrodes.

A bulk-acoustic wave resonator package includes a package substrate; a cover bonded to the package substrate; an acoustic wave resonator accommodated in an accommodation space defined by the package substrate and the cover; a conductive wire disposed in the accommodation space to electrically connect the acoustic wave resonator to the package substrate; and a bonding portion to fixedly couple the acoustic wave resonator to the package substrate. The bonding portion includes an adhesive member including silicon.

A quartz crystal resonator that includes an AT-cut quartz crystal blank including a first main surface and a second main surface that face each other and each of which has long sides extending in an X-axis direction of the quartz crystal blank and short sides extending in a Z′-axis direction of the quartz crystal blank, and a first side surface and a second side surface that are located adjacent to the long sides of the first main surface and the second main surface; a first excitation electrode and a second excitation electrode; and an extension electrode that extends from the first main surface to the second main surface along the first side surface and that is electrically connected to the first excitation electrode. Each the first and second side surfaces have a first m-plane face and a second m-plane face.

In a crystal oscillator, a crystal resonator and an IC chip are hermetically sealed in a package. The crystal resonator includes: a crystal resonator plate including a first excitation electrode formed on a first main surface, and a second excitation electrode, which makes a pair with the first excitation electrode, formed on a second main surface; a first sealing member covering the first excitation electrode of the crystal resonator plate; and a second sealing member covering the second excitation electrode of the crystal resonator plate. A vibrating part including the first excitation electrode and the second excitation electrode of the crystal resonator plate is hermetically sealed by bonding the first sealing member to the crystal resonator plate, and the second sealing member to the crystal resonator plate.

A quartz crystal resonator unit includes a quartz crystal resonator that includes a quartz crystal blank. A pair of excitation electrodes are disposed on opposed main surfaces of the quartz crystal blank so as to face each other. A pair of connection electrodes are electrically connected to respective ones of the pair of excitation electrodes. A base member has a surface on which the quartz crystal resonator is mounted. A lid member is joined to the surface of the base member via a joining member. The quartz crystal resonator is accommodated in an inner space defined by the lid member and the base member on the surface of the base member. Parts of the joining member that cover protruding portions are in contact with a side wall of the lid member so as to restrain movement of the lid member when seen in a plan view in a direction normal to the surface of the base member.

A piezoelectric vibration element that includes a piezoelectric piece having a first principal surface and a second principal surface; a via electrode penetrating the piezoelectric piece from the first principal surface to the second principal surface thereof; a conductive etch stop film covering the via electrode on the second principal surface; and a wiring electrode covering at least part of an outer edge of the conductive etch stop film on the second principal surface.

A method of manufacturing a piezoelectric resonator unit that includes preparing a piezoelectric resonator having a piezoelectric element, a pair of excitation electrodes respectively disposed on a first main surface and a second main surface of the piezoelectric element so as to face each other with the piezoelectric element therebetween, and a pair of connection electrodes that are respectively electrically connected to the pair of excitation electrodes; electrically connecting the pair of connection electrodes to a pair of electrode pads on a third main surface of a base member using an electroconductive holding member so as to excitably hold the piezoelectric resonator on the third main surface of the base member; and attaching an electroconductive material, which is scattered from an electroconductive member, to a surface of the electroconductive holding member.

A crystal oscillation element includes a crystal piece having principal planes defined by a first base axis and a second base axis that intersects the first base axis, and an excitation electrode unit at the principal planes of the crystal piece. The excitation electrode unit has flat plate portions and thick film portions located at electrode ends on the principal planes and that have a thickness larger than that of the flat plate portions. The thick film portion has first protruding portions at the ends in the axis direction of the first base axis, extend in the axis direction of the second base axis and protrude from the flat plate portion, and second protruding portions at the ends in the axis direction of the second base axis, extend in the axis direction of the first base axis and protrude from the flat plate portion.

A quartz crystal resonator unit that includes: a piezoelectric blank; a first excitation electrode on a first principal surface and within at least a part of a vibration portion of the piezoelectric blank; a second excitation electrode on a second principal surface and within at least a part of the vibration portion of the piezoelectric blank; a first extended electrode on the first principal surface and electrically connected to the first excitation electrode; and a second extended electrode on the second principal surface and electrically connected to the second excitation electrode; and an insulation layer including a hollow portion which defines a space with the second excitation electrode. A thickness of the first extended electrode is larger than a thickness of the second extended electrode. An end portion of the first extended electrode extends over the hollow portion in a plan view of the piezoelectric vibrator.

A crystal device includes a bearing base, an integrated chip and a conductive adhesive unit. The bearing base includes a conductive seat. The integrated chip includes a principal reference plane facing the conductive seat, and having a first major axis. The conductive adhesive unit has a second major axis and an aspect ratio, and is at least partly disposed between the conductive seat and the integrated chip. The aspect ratio ranges from 1.1 to 1.9. The principal reference plane further has a perpendicular projection straight line defined according to the second major axis. A practical angle is included by the first perpendicular projection straight line and the first major axis, and ranges from 0 degree to 90 degrees.